1. Field of the Invention
The present invention relates to a pressure distribution measuring system for measuring a pressure distribution along a predetermined fluid flow direction on a surface of an object moving relative to a fluid.
2. Description of Background Art
A pressure distribution measuring system for measuring a pressure distribution along a predetermined fluid flow direction on a surface of an object moving relative to a fluid is used in many fields such as aircraft, marine vessels, automobiles, buildings and bridge beams.
For example, in the field of aviation, Japanese Patent Application Laid-open No. 2002-206987 discloses a wing model used for measuring a pressure distribution along a cord line on a wing surface in a wind tunnel test, in which a plurality of pressure detecting bores are formed to open in the wing surface, and a plurality of passages are formed within the wing model to connect the pressure detecting bores to pressure sensors.
Also, Published Japanese Translation No. 2003-500640 of PCT Application No. PCT/DE00/01468 discloses a pressure distribution measuring system in which a piezo-foil is bonded to an inner surface of a wing shell fixed to cover an opening formed in a wing surface of an actual airplane. Vibration of the wing shell caused by airflow along the wing surface is detected based on a signal output from the piezo-foil.
If the plurality of pressure detecting bores opening in the wing surface are formed along the cord line as disclosed in Japanese Patent Application Laid-open No. 2002-206987, the following problems occur: turbulence of airflow caused by the upstream pressure detecting bore affects the downstream pressure detecting bore, thereby degrading the accuracy in measuring a pressure distribution, and also pressure loss and pressure leakage caused by the passages formed within the wing model for connecting the pressure detecting bores to the pressure sensors affect the measuring accuracy; time lag is generated in the measurement, because the passages are long; a measurable pressure range is narrow; the measuring accuracy degrades due to stain and dust adhering to the pressure detecting bores; and the measurement in water (in the case of marine vessels) is impossible.
Also, in Published Japanese Translation No. 2003-500640 of PCT Application No. PCT/DE00/01468, the wing shell having the piezo-foil bonded to its inner surface is fixed to cover the opening formed in the wing surface, leading to a problem that a step or a gap is generated along an outer periphery of the wing shell to cause turbulence of airflow. Further, the piezo-foil has a characteristic of outputting a signal upon deformation but not outputting the signal in a steady state in which deformation amount is constant, leading to a difficulty in measuring a pressure distribution on the wing surface in the steady state.